Immunology of primary biliary cirrhosis and primary sclerosing cholangitis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown aetiology characterized by high titre serum antimitochondrial autoantibodies (AMA), a striking female predominance, and an autoimmune-mediated destruction of the small and medium-size intrahepatic bile ducts1. PBC is a peculiar, yet representative, organ-specific autoimmune disease. The presence of serum AMA and autoreactive T and B cells, in conjunction with the co-occurrence of other autoimmune diseases, implies an autoimmune pathogenesis for PBC. A complex genetic background is suggested by the incidence of the disease among first-degree relatives2, the high concordance rate among twins3, and the proposed role for sex chromosome defects4. To summarize, PBC onset recognizes two necessary components: i.e. a permissive genetic background and an environmental trigger.